1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
#include <stddef.h>
#include "frida-gumjs.h"
#include "config.h"
#include "instrument.h"
#include "ranges.h"
#include "stalker.h"
#include "util.h"
#define G_MININT33 ((gssize)0xffffffff00000000)
#define G_MAXINT33 ((gssize)0x00000000ffffffff)
#define PAGE_MASK (~(GUM_ADDRESS(0xfff)))
#define PAGE_ALIGNED(x) ((GUM_ADDRESS(x) & PAGE_MASK) == GUM_ADDRESS(x))
#if defined(__aarch64__)
__attribute__((aligned(0x1000))) static guint8 area_ptr_dummy[MAP_SIZE];
#pragma pack(push, 1)
typedef struct {
// cur_location = (block_address >> 4) ^ (block_address << 8);
// shared_mem[cur_location ^ prev_location]++;
// prev_location = cur_location >> 1;
// stp x0, x1, [sp, #-160]
// adrp x0, 0x7fb7ff4000
// ldr x1, [x0]
// mov x0, #0x18b8
// eor x0, x1, x0
// adrp x1, 0x7fb7d73000
// add x0, x1, x0
// ldrb w1, [x0]
// add w1, w1, #0x1
// tbz w1, #8, 0x7fb6f0dec8
// mov w1, #0x1
// strb w1, [x0]
// adrp x0, 0x7fb7ff4000
// mov x1, #0xc5c
// str x1, [x0]
// ldp x0, x1, [sp, #-160]
// b 0x7fb6f0dee4
// ldp x16, x17, [sp], #144
uint32_t stp_x0_x1; /* stp x0, x1, [sp, #-0xa0] */
uint32_t adrp_x0_prev_loc1; /* adrp x0, #0xXXXX */
uint32_t ldr_x1_ptr_x0; /* ldr x1, [x0] */
uint32_t mov_x0_curr_loc; /* movz x0, #0xXXXX */
uint32_t eor_x0_x1_x0; /* eor x0, x1, x0 */
uint32_t adrp_x1_area_ptr; /* adrp x1, #0xXXXX */
uint32_t add_x0_x1_x0; /* add x0, x1, x0 */
uint32_t ldrb_w1_x0; /* ldrb w1, [x0] */
uint32_t add_w1_w1_1; /* add w1, w1, #1 */
uint32_t tbz_w1_8_8; /* tbz w1, #8, #8 */
uint32_t mov_w1_1; /* mov w1, #1 */
uint32_t strb_w1_ptr_x0; /* strb w1, [x0] */
uint32_t adrp_x0_prev_loc2; /* adrp x0, #0xXXXX */
uint32_t mov_x1_curr_loc_shr_1; /* movz x1, #0xXXXX */
uint32_t str_x1_ptr_x0; /* str x1, [x0] */
uint32_t ldp_x0_x1; /* ldp x0, x1, [sp, #-0xa0] */
uint32_t b_imm8; /* br #8 */
uint32_t restoration_prolog; /* ldp x16, x17, [sp], #0x90 */
} afl_log_code_asm_t;
#pragma pack(pop)
typedef union {
afl_log_code_asm_t code;
uint8_t bytes[0];
} afl_log_code;
static const afl_log_code_asm_t template =
{
.stp_x0_x1 = 0xa93607e0,
.adrp_x0_prev_loc1 = 0x90000000,
.ldr_x1_ptr_x0 = 0xf9400001,
.mov_x0_curr_loc = 0xd2800000,
.eor_x0_x1_x0 = 0xca000020,
.adrp_x1_area_ptr = 0x90000001,
.add_x0_x1_x0 = 0x8b000020,
.ldrb_w1_x0 = 0x39400001,
.add_w1_w1_1 = 0x11000421,
.tbz_w1_8_8 = 0x36400041,
.mov_w1_1 = 0x52800021,
.strb_w1_ptr_x0 = 0x39000001,
.adrp_x0_prev_loc2 = 0x90000000,
.mov_x1_curr_loc_shr_1 = 0xd2800001,
.str_x1_ptr_x0 = 0xf9000001,
.ldp_x0_x1 = 0xa97607e0,
.b_imm8 = 0x14000002,
.restoration_prolog = 0xa8c947f0,
}
;
gboolean instrument_is_coverage_optimize_supported(void) {
return true;
}
static gboolean instrument_coverage_in_range(gssize offset) {
return (offset >= G_MININT33 && offset <= G_MAXINT33);
}
static void instrument_patch_ardp(guint32 *patch, GumAddress insn,
GumAddress target) {
if (!PAGE_ALIGNED(target)) { FATAL("Target not page aligned"); }
gssize distance = target - (GUM_ADDRESS(insn) & PAGE_MASK);
if (!instrument_coverage_in_range(distance)) {
FATAL("Patch out of range 0x%016lX->0x%016lX = 0x%016lX", insn, target,
distance);
}
guint32 imm_low = ((distance >> 12) & 0x3) << 29;
guint32 imm_high = ((distance >> 14) & 0x7FFFF) << 5;
*patch |= imm_low;
*patch |= imm_high;
}
void instrument_coverage_optimize(const cs_insn * instr,
GumStalkerOutput *output) {
afl_log_code code = {0};
GumArm64Writer *cw = output->writer.arm64;
guint64 area_offset = instrument_get_offset_hash(GUM_ADDRESS(instr->address));
gsize map_size_pow2;
gsize area_offset_ror;
GumAddress code_addr = 0;
if (instrument_previous_pc_addr == NULL) {
GumAddressSpec spec = {.near_address = cw->code,
.max_distance = 1ULL << 30};
instrument_previous_pc_addr = gum_memory_allocate_near(
&spec, sizeof(guint64), 0x1000, GUM_PAGE_READ | GUM_PAGE_WRITE);
*instrument_previous_pc_addr = instrument_hash_zero;
FVERBOSE("instrument_previous_pc_addr: %p", instrument_previous_pc_addr);
FVERBOSE("code_addr: %p", cw->code);
}
// gum_arm64_writer_put_brk_imm(cw, 0x0);
code_addr = cw->pc;
code.code = template;
/*
* Given our map is allocated on a 64KB boundary and our map is a multiple of
* 64KB in size, then it should also end on a 64 KB boundary. It is followed
* by our previous_pc, so this too should be 64KB aligned.
*/
g_assert(PAGE_ALIGNED(instrument_previous_pc_addr));
g_assert(PAGE_ALIGNED(__afl_area_ptr));
instrument_patch_ardp(
&code.code.adrp_x0_prev_loc1,
code_addr + offsetof(afl_log_code, code.adrp_x0_prev_loc1),
GUM_ADDRESS(instrument_previous_pc_addr));
code.code.mov_x0_curr_loc |= area_offset << 5;
instrument_patch_ardp(
&code.code.adrp_x1_area_ptr,
code_addr + offsetof(afl_log_code, code.adrp_x1_area_ptr),
GUM_ADDRESS(__afl_area_ptr));
map_size_pow2 = util_log2(__afl_map_size);
area_offset_ror = util_rotate(area_offset, 1, map_size_pow2);
instrument_patch_ardp(
&code.code.adrp_x0_prev_loc2,
code_addr + offsetof(afl_log_code, code.adrp_x0_prev_loc2),
GUM_ADDRESS(instrument_previous_pc_addr));
code.code.mov_x1_curr_loc_shr_1 |= (area_offset_ror << 5);
gum_arm64_writer_put_bytes(cw, code.bytes, sizeof(afl_log_code));
}
void instrument_coverage_optimize_init(void) {
char *shm_env = getenv(SHM_ENV_VAR);
FVERBOSE("SHM_ENV_VAR: %s", shm_env);
if (shm_env == NULL) {
FWARNF("SHM_ENV_VAR not set, using dummy for debugging purposes");
__afl_area_ptr = area_ptr_dummy;
memset(area_ptr_dummy, '\0', sizeof(area_ptr_dummy));
}
FVERBOSE("__afl_area_ptr: %p", __afl_area_ptr);
}
void instrument_flush(GumStalkerOutput *output) {
gum_arm64_writer_flush(output->writer.arm64);
}
gpointer instrument_cur(GumStalkerOutput *output) {
return gum_arm64_writer_cur(output->writer.arm64);
}
#endif
|
